A gunman killed six people and wounded two in apparently random shootings in Kalamazoo County, Michigan, before being arrested early on Sunday, a prosecutor said. A television station reported the suspect was an Uber driver who took fares between shootings.

The 45-year-old suspect, Jason Dalton, was believed to have opened fire late on Saturday outside an apartment complex, a Kia car dealership and a Cracker Barrel restaurant over a period of little more than four hours, Kalamazoo County prosecutor Jeff Getting said.

The victims "appear to be chosen at random, because they were available," he said at a news conference. "They were shot multiple times, multiple - nine, 10, 11 shell casings at each of these scenes."

The carnage in Kalamazoo, a city of about 75,000 people 150 miles (240 km) west of Detroit, was the latest in a series of mass shootings that have made gun control a campaign issue before the November U.S. presidential election.

WOOD TV, a Grand Rapids station, quoted police as saying that they were investigating reports that Dalton dropped off Uber fares at a Fairfield Inn hotel. He then went to the nearby Cracker Barrel and killed four women and seriously wounded a 14-year-old girl.

The station reported that Getting said authorities were investigating a Facebook post by the fiance of an Uber passenger, who said that Dalton had sideswiped a car, run a stop sign and was driving erratically just before the shootings.

An Uber representative confirmed that Dalton was a driver for the car-hailing service and said that he had passed background checks. In a emailed statement, the company's chief security officer, Joe Sullivan, said Uber was contacting police to help with the investigation.

Getting told reporters he believed police had recovered Dalton's cellphone. Dalton was thought to have been in contact with more than one person during the shooting spree, he said.

Dalton was arrested in downtown Kalamazoo at about 12:30 a.m. Getting said he expected Dalton to be arraigned on Monday on charges of murder, assault and firearms violations.

The carnage began about 6 p.m. on Saturday when a woman was wounded outside an apartment building. At about 10 p.m., two men, who Getting said were related, were killed at the car dealership.

The shooting at the Cracker Barrel took place about 15 minutes later, Getting said. Getting said a semi-automatic pistol was found in his car when he was arrested.

Police said Dalton had no known criminal record. The victims' names were not released.